1. Field of the Invention
The present invention relates to a drawing apparatus which has a drawing data correcting function, the drawing data representing a pattern to be drawn.
2. Description of the Related Art
When drawing patterns on a substrate, patterns should be drawn at a predetermined position. However, a substrate can be slightly transformed due to heating processes and so on, and the actual position of the drawn pattern can shift from an ideal position. Therefore, generally, marks for determining pattern position are previously provided at predetermined positions, such as the corner of the substrate. Then, distances of the marks before and after the transformation of the substrate are measured, and the drawing data is corrected based on the distances of the marks.
In drawing data correction operations, generally, correction processes are carried out for the original drawing data representing circuit patterns which should be drawn, so that the original drawing data becomes corrected drawing data representing circuit patterns that are enlarged, reduced, rotated or moved parallel to the original position, and so on.
In a case where the transformation of a substrate is complex, the above mentioned data correction operations, such as for enlargement or reduction of the circuit patterns, and position change of the circuit patterns, based on the distances of the marks, are not accurate enough for pattern drawing.